In U.S. Pat. No. 4,310,519 to Albers-Schonberg et al., are disclosed C-076 natural products (now referred to as avermectin compounds) which are prepared from the culturing of Streptomyces avermitilis. In U.S. Pat. No. 4,199,569 to Chabala et al., the 22,23-dihydro reduction products of avermectin compounds are disclosed along with procedures for the removal of one or both of the .alpha.-L-oleandrose sugar groups at the 13-position. The natural configuration of the 13-position oxygen atom has been found to be .alpha.(below the plane of the ring). The instant invention involves the bioconversion of synthetically prepared 13-epi-22,23-dihydro avermectin Bla/Blb aglycone into 13-epi avermectin glycosylated compounds.